| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- G N A T . T A B L E -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1998-2005, AdaCore -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, -- |
| -- Boston, MA 02110-1301, USA. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with System; use System; |
| with System.Memory; use System.Memory; |
| |
| with Unchecked_Conversion; |
| |
| package body GNAT.Table is |
| |
| Min : constant Integer := Integer (Table_Low_Bound); |
| -- Subscript of the minimum entry in the currently allocated table |
| |
| Max : Integer; |
| -- Subscript of the maximum entry in the currently allocated table |
| |
| Length : Integer := 0; |
| -- Number of entries in currently allocated table. The value of zero |
| -- ensures that we initially allocate the table. |
| |
| Last_Val : Integer; |
| -- Current value of Last |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| procedure Reallocate; |
| -- Reallocate the existing table according to the current value stored |
| -- in Max. Works correctly to do an initial allocation if the table |
| -- is currently null. |
| |
| pragma Warnings (Off); |
| -- Turn off warnings. The following unchecked conversions are only used |
| -- internally in this package, and cannot never result in any instances |
| -- of improperly aliased pointers for the client of the package. |
| |
| function To_Address is new Unchecked_Conversion (Table_Ptr, Address); |
| function To_Pointer is new Unchecked_Conversion (Address, Table_Ptr); |
| |
| pragma Warnings (On); |
| |
| -------------- |
| -- Allocate -- |
| -------------- |
| |
| function Allocate (Num : Integer := 1) return Table_Index_Type is |
| Old_Last : constant Integer := Last_Val; |
| |
| begin |
| Last_Val := Last_Val + Num; |
| |
| if Last_Val > Max then |
| Reallocate; |
| end if; |
| |
| return Table_Index_Type (Old_Last + 1); |
| end Allocate; |
| |
| ------------ |
| -- Append -- |
| ------------ |
| |
| procedure Append (New_Val : Table_Component_Type) is |
| begin |
| Increment_Last; |
| Table (Table_Index_Type (Last_Val)) := New_Val; |
| end Append; |
| |
| -------------------- |
| -- Decrement_Last -- |
| -------------------- |
| |
| procedure Decrement_Last is |
| begin |
| Last_Val := Last_Val - 1; |
| end Decrement_Last; |
| |
| ---------- |
| -- Free -- |
| ---------- |
| |
| procedure Free is |
| begin |
| Free (To_Address (Table)); |
| Table := null; |
| Length := 0; |
| end Free; |
| |
| -------------------- |
| -- Increment_Last -- |
| -------------------- |
| |
| procedure Increment_Last is |
| begin |
| Last_Val := Last_Val + 1; |
| |
| if Last_Val > Max then |
| Reallocate; |
| end if; |
| end Increment_Last; |
| |
| ---------- |
| -- Init -- |
| ---------- |
| |
| procedure Init is |
| Old_Length : constant Integer := Length; |
| |
| begin |
| Last_Val := Min - 1; |
| Max := Min + Table_Initial - 1; |
| Length := Max - Min + 1; |
| |
| -- If table is same size as before (happens when table is never |
| -- expanded which is a common case), then simply reuse it. Note |
| -- that this also means that an explicit Init call right after |
| -- the implicit one in the package body is harmless. |
| |
| if Old_Length = Length then |
| return; |
| |
| -- Otherwise we can use Reallocate to get a table of the right size. |
| -- Note that Reallocate works fine to allocate a table of the right |
| -- initial size when it is first allocated. |
| |
| else |
| Reallocate; |
| end if; |
| end Init; |
| |
| ---------- |
| -- Last -- |
| ---------- |
| |
| function Last return Table_Index_Type is |
| begin |
| return Table_Index_Type (Last_Val); |
| end Last; |
| |
| ---------------- |
| -- Reallocate -- |
| ---------------- |
| |
| procedure Reallocate is |
| New_Size : size_t; |
| |
| begin |
| if Max < Last_Val then |
| pragma Assert (not Locked); |
| |
| while Max < Last_Val loop |
| |
| -- Increase length using the table increment factor, but make |
| -- sure that we add at least ten elements (this avoids a loop |
| -- for silly small increment values) |
| |
| Length := Integer'Max |
| (Length * (100 + Table_Increment) / 100, |
| Length + 10); |
| Max := Min + Length - 1; |
| end loop; |
| end if; |
| |
| New_Size := |
| size_t ((Max - Min + 1) * |
| (Table_Type'Component_Size / Storage_Unit)); |
| |
| if Table = null then |
| Table := To_Pointer (Alloc (New_Size)); |
| |
| elsif New_Size > 0 then |
| Table := |
| To_Pointer (Realloc (Ptr => To_Address (Table), |
| Size => New_Size)); |
| end if; |
| |
| if Length /= 0 and then Table = null then |
| raise Storage_Error; |
| end if; |
| |
| end Reallocate; |
| |
| ------------- |
| -- Release -- |
| ------------- |
| |
| procedure Release is |
| begin |
| Length := Last_Val - Integer (Table_Low_Bound) + 1; |
| Max := Last_Val; |
| Reallocate; |
| end Release; |
| |
| -------------- |
| -- Set_Item -- |
| -------------- |
| |
| procedure Set_Item |
| (Index : Table_Index_Type; |
| Item : Table_Component_Type) |
| is |
| begin |
| if Integer (Index) > Last_Val then |
| Set_Last (Index); |
| end if; |
| |
| Table (Index) := Item; |
| end Set_Item; |
| |
| -------------- |
| -- Set_Last -- |
| -------------- |
| |
| procedure Set_Last (New_Val : Table_Index_Type) is |
| begin |
| if Integer (New_Val) < Last_Val then |
| Last_Val := Integer (New_Val); |
| else |
| Last_Val := Integer (New_Val); |
| |
| if Last_Val > Max then |
| Reallocate; |
| end if; |
| end if; |
| end Set_Last; |
| |
| begin |
| Init; |
| end GNAT.Table; |
